Method of heating



June 23, 1925. 1,542,953

F. FUENING METHOD OF HEATING Filed July 16. 1920 6/15 Pl/MP I M PUMP Patented June '23, 1925.

. UNITED sTjATE's' PATENT OFFICE.

'l l ram rummmor cm'cseo, Immoralm'rnon or name.

Application am July 10, mo. s mi no. 896,688.

To all whom it may comem:

, Be it known that I, "FRANZ PUENING, a citizen of Germany, residing at Chic'ahgo, in the county of Cook and State of I nois, have invented certain new and useful Improvements in Methods of Heating, of which the following is a-specification.

. In the following specification my -improved method of heating will be described as applied to the heating of retorts' for the making of low tempera'turecoketo which it is very well adapted, though it is to be understood that the invention is of wide application where similar conditions of heating object of the invention to increase the of flow of the gases in contact with theare desirable. In coking coal' at low temperatures the coal to be coked"is ordinarily separated from the hot gasesand products of combustion supplying the coking heat by the wall of the retort, which being commonly made of clay and silica material, is of very low heat conductivity, and thereforethe "rate of heat transfer from the gases to the coal is very low. In order to improve the rate of.

transfer it has' been proposed to make the vertical retort walls of ironbecause of the superiority of the heat conductivity-of the metal ascompared to that of the clay and silica material commonly used. However,

iron has the distinct and serious disadvantage for the p'urpose that it isvery sensitive to overheating and is quickly ruined when heated too high. While therefore it is necessary not to exceed the critical temperature with respect to the iron of the retort it is desirable that the heating gases approach this temperature as nearly as is safe in order to. attain the highest practicable rate of heat transfer. It is the object of my invention to so control the temperature of the hot gases and products of combustion by which the retorts are. heated as to closely approach without actually reaching a temperature at which the iron is injured- It is a further speed retorts or other objector ob'ects to be heated, and in this manner bot with the retort and by bringinga larger volume of hot gases per unit of time into contact with the 'retort's to further increase. the speed of communication of heat.

It is a further ob'ect of m "invention to effect a proper distribution 0 heat over the entire, surface of the retorts or objects to be heated and to avoid localized superheating.

' sump'tion.

by scour-' ing away the dead layer of gases in contact It is known that the tem rature of comtheir "temperature reduced considerably below the temperature of combustion. The products of combustion so supplied are re turned and intermingled with. the newly formed products of combustion in fixed'proportion and as the proportion of new and old products of combustion is thus care.--

fullyregulatedand the temperatures of each properly redetermined, it is )possible to regulate t e temperature of the in contact with the iron retorts or other objects to be heated to a nicety.

-In the accompanying drawingls I have shown somewhat diagrammatica y a preferred means for carr ing'my invention mto effect. It is to be uml erstood, however, that the specific disclosure is for the purpose of exemplification onl and that'the scope .of

the invention is efined in the following claims in which l have endeavored-to distingui'sh ,it from the prior art so far as known tome without, however, relinquishing or. abandoning any portion or feature thereof. v

In the accompanying drawings Fig; 1 is,

a diagrammatic representation partly m section of a preferred form of apparatus embodying and adaptedto carry out my invention; and Fi 2 a fragmentary detail of a somewhat mod ed construction of the same.

In the drawings I have shown at 3 a diagrammatic representation of a bench of iron retorts for the purpose of making low temperature coke, though it is to be. understood as heretofore pointed out that these retor ts are merely representative of a variety of objectswhich may be heated the use of f my invention. The retorts tare arranged in a series of horizontal layers, with heating fines or passages 5 between the same. A chamber 6 surrounds the bench of retorts and communicates at its ends with the pans sage 5. Combustion chambers 7, 7 are arranged at the respective opposite ends of the chamber 6 and are supplied with gas by branch pipes 8, 8, connecting by main 9' with the gas pump 10. The air for supporting combustion is supplied by an air pump 11 which is connected by branch pipes 12, 13 respectively, with heating coils 14, 15 heated in a manner to be presently described, and said heating coils are in turn connected by. pipes or conduits 16, 17 to the aforesaid combustion chambers 7, 7, respectively.

Connected to each combustion chamber 7 is a storage chamber 18 which is adapted to receive and store products of combustion after they have been circulated through or in contact with the object to be heated, and in the lower part of said storage chambers are the air heating coils 14c, 15 respectively, to which references has heretofore been made. A cylinder 19-of large capacity communicates at its respective opposite ends with the chambers 18, 18 and a piston 20 is reciprocable in said cylinder. Obviously by moving the piston in one direction it creates pressure in the chamber 18 toward which it is moved, forcing a portion of the gases contained therein into the combustion chamber 7 with which it communicates, the motion of the piston at the same time drawing an, additional amount of gases from the other combustion chamber into the storage chamber 18 communicating therewith. The branch gas pipes 8, 8 and the branch air pipes 12, 13 are provided with reversible valves which are reversed at each operation of the piston 20, preferably by electric means of an obvious character common to said reversing valves and said piston, so that the supplies of air, combustible gas and products of combustion are all reversed simultaneously, the chambers 7 and 8 being thus alternately supplied with mixtures of these gases. The resulting products of combustion comprising those freshly formed and the cooled products of combustion pass in contact with the object to be heated and then to the opposite combustion chamber and storage chamber.

The amounts of air and gas which are burned in combustion chambers 7 are ignited inthe beginning of the operation through openings 27,'but after a sufficient ength of operation the walls of the combustion chambers 7 become so hot that reignition from the outside is unnecessary, the combustible mixture igniting upon contact with the hot walls. To obtain this effect more surely the combustion chambers 7 in Fig. 1 are shown to be rather long and remote from the gas passages for old combustion gases between storage rooms 18' and chamber 6, thereby preventing the temperature of their walls from dropping below the temperature of ignition of the additional fuel gas,

nuance As an additional amount of products of combustion is formed at each reversal the total-amount is in excess of the capacity of the storage chamber into which the gases are discharged. In order to take care of the excess each storage chamber is provided with an outlet valve 21, 21,50 weighted or springpressed or operated as to withstand the pressure under which the products of combustion are forced therefrom into the corresponding combustion chamber, but to yield to permit the escape of excess gases.

When the piston is not in motion, both valves stand partly open and ready'to relieve any additional gas that may be introduced through pipes 16, 17, 8 and 8'. However, as soon as the piston is moved for instance to the left and thus the gaspushed from the left chamber 18 through the retort into the right chamber 18, friction develops in all gas passages which is overcome only by a sufficient static gas pressure building up on the left side of the piston. The result is that valve 21 to the left is automatically closed by this pressure while valve 21 to the right, being under no pressure remains open and releases the necessary amount of gas.

The capacity of each chamber 18 is preferably approximatel twice the effective capacity of the cylin er 19 as determined by diameter and length of stroke. As the small increment of fresh products of combustion is received at each reversal of the piston, being formed by combustion 'within the chamber 7 there is a step by step travel of the gases down the respective chambers 18 and out atthe valves 21. readily understood by following the action of the device step by step. When the piston moves to the right avolume of gas equal to the capacity of the cylinder is forced from the right hand chamber 18 into the corresponding combustion chamber 7 where it mixes with an additional amount of freshly formed products of combustion, the mixture flowing through chamber 6 in contact with the objects to be heated and into the left hand storage chamber 18. The movement of the piston 20 to the right at the same time has created a space equal to its capacity, for the reception of gas in the left hand storage chamber but the gas which must be actually received exceeds this amount by the amount of fresh products of This will be more combustion formed in the combustion chamber 7. If the capacity of the respective chambers 18 is just double that ofjthe cylinder 19 the gases received into the left hand 1 cylinder 18 would fill the upper half thereof and a small space below the upper half deof the piston to the left a volume of gases equaling the volume of cylinder 19 is expelled from the left hand chamber and mixed with fresh products of combustion and forced into the right hand chamber. On the next movement of the piston to the right a volume of products of combustion exceeding the capacity of the cylinder 19 by the amount of newly formed products of combustion is received in the left hand storage chamber 18 and so on. The valves 21 therefore release at each motion of the piston awa from them respectively, amounts of products of combustion corresponding-to the amounts thereof freshly formed at 'each reciprocation of the piston and therefore there is a step by step movement of the gases down the respective storage chambers, and as these gases are gradually cooled during the descent particularly by the respective coils 14-15 those in contact with the cylinder are so cool as not to injuriously afl'ect it while the hottest gases are stored in the upper portions of the respective storage chambers and forced back and forth in 'contact with the battery of retorts or other ob jects to 'be heated. Thus between the cylinder and the battery of retorts there is on each side a cushion of gas which permits hot gases to be used in contact with the retorts or other objects to be heated while the cylinder is directly in contact with relatively cold gases. Thus the heat of the hot gases is preserved durin storage and maintained by the addition 0 small amounts of fresh products of combustion burned in the combustion chamber. By properly regulating the amount of gas and air for supporting combustion the temperature of the gases in' cont-act with the retorts or other objects tobe heated can be readilyregulated as desired. The retorts or other objects to be heated are very uniformly heated by reason of the alternate, and rapid movement of the heating gases and it is possible because of the rapid flow of the gases to secure a rapid transfer of heat with relatively low temperature of the gases from which the heatis supplied. Thus rapid communication of heat I is effected with great uniformity and without local overheating, Such equal distribution of heat is most importantin the making of low temperature coke for even if the cross-sectional areas of all the passage ways between the retorts are equal and, their internal condition as to smoothness of surface, etc.,'is the same ithas been found almost impossible to, obtain equal distribution of heating gases to the passages because of,

other disturbing influences such as the tendency of a slightly" hotter and therefore lighter portion of gas to travelfaster than the cooler portion, vor because of uneven conditions in the larger flues leading up to 'the passages between the retorts. By increasing the speed of gases as described these disturbing influences are overcome and inggas isburn'ed are walled off and the products of combustion carried by a heating coil 26 of fire brick or other suitable material through the flues 7' 7 through which the gases from the storage chambers 18' 18' travel and thereby suitably raise the temperature of said gases. Obviously in this construction the valves 21 may bedone away with and any suitable gas may be used as it is merely forced from one chamber 18 to the other through passages 7 and the heating chamber 6'' without receiving any additional volumes of gases. The material of which the coils 26 are made, absorbs and stores a good deal of heat, depending of course on the specific heat of the material. Therefore the coils will give off heat into the reciprocated gas no matter if the stroke of the piston is to the left or to the right. It is obvious that this steady re lenishment of the heat of the reciprocate gases can also be accomplished in the case illustrated in Fig. 1, by merely letting the gas flames in combustion chambers 7 burn continuously instead of alternatingly and in synchronism with the motions of the piston, as described before.

Iclaim: g v I I 1. In a device of the class described, a heating chamber provided with a. pair of combustion chambers, means for introducing fuel and air to each of said chambers, a storage chamber for theproducts of combustion communicating with each of said combustion chambers, and-means for alternately storing" and discharging a predetermined amount of the products of combustion in each of said storage chambers.

, 2. In a device of the. class described, a heating chamber having combustion cham-.

heatingchamber, oppositely arranged eom-' bustion chambers, means forsupplying airy and fuel to the respective combustion chambers, a storage chamber forthe products of combustion communicating with each combustion chamber, a cylinderconnecting with bers communicating; therewith, means for I of each storage chamber into the corre each storage chamber, and a piston in said cylinder.

chambers communicating therewith, means.

for supplying air and fuel to each said combustion chamber, a storage chamber communicating with each said combustion chamber, a cylinder, a piston therein, the capacity of the cylinder being less than the capacity of 'the storage chamber whereby the hot products of combustion are prevented from contact with said cylinder.

5. In a device of the class described, a heating chamber. a pair of combustion chambers communicating therewith, a storage chamber communicating with each said combustion chamber and adapted to receive products of combustion therefrom, means for cooling a portion of the products of combustion outside of said storage chamber, means for supplying air and fuel to each said combustion chamber and means for alternately increasing and decreasing the effective storage capacity of said storage chambers.

6. In a device of the class described, a heating chamber, a pair of combustion chambers communicating therewith, means for supplying air and fuel to each said combustion chamber, a storage chamber com municating with each said combustion chamber, a cylinder communicating with each said storage chamber at a point thereof remote from its connection to the corresponding'combustion chamber and a piston in said cylinder. I

7. In a device of the class described, a heating chamber, a pair of combustion chambers communicating therewith, means for supplying air and fuel to, each said combustion chamber, a storage chamber communicating with each said combustion chamber, an outlet valve adapted to release a portion of the contents from said storage. chamber equivalent in amount to the supplied air and fuel.

8. In a device ofthe class described, a heating chamber, a pair of combustion chambers communicating therewith, a storage chamber communicating with each said combustion chamber, a. heat recuperating chamberconnected with each'storage chamber, an air-coil within each said recuperating chamber, means for supplying said coil with air, a connection from each said air coil to the corresponding combustion chamber .and means for forcing a portion of the contents sponding combustion chamber.

9. A process of heating which consistsin burning a mixture of fuel and air, adding to the products of combustion a cooler gas, passing the mixture so. formed into contact with the object to be h eated1 storing a porterraces tion of such used gases and mixing such cooled and stored gases with fresh products of combustion and repassing them in the opposite direction in contact with the object to be heated. i

10. A process of heating which consists in burning a predetermined quantity of air and fuel, mixing with the products ofcombustion a predetermined volume of cooled products of combustion, passing the mixture into contact with the object to be heated, storing a portion of the gases, burning an additional predetermined supply of air and fuel, mixing the fresh products of combustion with the stored portion of gases and passing the mixture in contact with the object to be heated.

11. A method of heating a body to a predetermined temperature which consists in forcibly and with great speed reciprocating a fixed volume of heating gases of proper temperature over the surfaces of the body and raising the temperature of the gases before returning them to the body to resupply that amount of heat that has been absorbed by the body.

12. A method of uniformly heating a retort having many passages for heating gas which consists in forcibly and positively reciprocating a fixed volume of heating gas through said passages and adjusting the speed of the gases in relation to'the crosssectional area of the passages in such a way that a sufficient drop of pressure through said passages is created, in order to assure uniform heating of the retort.

13. A method of reciprocating a body of hot heating gases through a space to be heated by means of a mechanical device which consists in interposing between the mechanical device and the heating gases, a cushion of other gases of a graded temperature, the hottest portion of which is incontact with the heating gases while its coldest portion is in contact with the mechanical device.

14-. A method of heating a space which consists in providing store rooms for heating gases adjacent that space and using mechanical means for pushing the heating over the surface of the body to be heated" and maintaining the temperature of the heating gases by adding heat thereto.

16.- In a device of the class described, a

heating chamber, a gas storage chamber, means for alternately forcing eating gas from the storage chamber-into the heating chamber and withdrawing it from the latter into the storage chamber, and means for increasing the temperature of the heating gas.

17. In a device of the class described, a-

heating chamber, gas storage chambers connected to opposite sides thereof, means for forcing gas from one storage chamber through the heating chamber to the other storage chamber and means for heating the gas.

18. In a device for the exchange of heat, a chamber adapted to receive the body the temperature of which is to be affected, a chamber in communication therewith, means for reciprocating a heat exchange medium alternately from the one chamber to the other, and means for heating the exchange medium when out of contact with the body whose temperature is to be affected.

19. In a device of the class described, a

chamber adapted to contain a body whose temperature is'to be raised and a heat exchange fluid medium in contact therewith, a cylinder having an opening at each end, a displacement piston in said cylinder, and connections between the said cylinder openings and the ends of said chamber, whereby at each stroke of the piston a volume of said medium equal to the volume displaced by the piston is caused to flow through said chamber,

20. In a device of the class described, a chamber adapted to contain a body the temperature of which is to be changed, a cylinder of a capacity at least equal to that of the said chamber connected thereto, and a piston reciprocating in said cylinder whereby at each stroke of the piston a complete movement of the heating medium is effected.

21. In a device of the class described, a chamber adapted to contain a body to be heated, a chamber communicating therewith and provided with heating means, a displacement means for reciprocating a heat exchange fluid medium alternately from one chamber to the other, the capacity of the displacement means being such as to accomplish the complete movement of the medium in a single stroke.

22. A method of heating bodies which consists in exposing the bodies to quick pulsations of the heating gases over their surfaces, the pulsations being eifected alternately in opposite directions.

23. The combination with a recuperative furnace for heating bodies to a medium temperature, of means for effecting quick pulsations of the heating gases back and forth over the surfaces of the bodies and the recuperator, for the urpose of creatin uniform temperatures in said bodies an eflicient heat transfer into said bodies and into the recuperator.

24. A method of heating which consists in pulsating a large body of hot gases back .ber, of means for reciprocating hot gases therethrough, heat preserving'storage chambers for hot gases located adjacent to the heating chamber and between the heating chamber and the means for reciprocation, and means for recuperation of heat from the waste gases located between the storage chambers and the means for reciprocation.

26. The combination with a recuperative -heating furnace, of means for effecting uick pulsation of hot' gases back and orth through the heating chamber, the recuperators of the furnace being located in the current of pulsated gases, but at a distance from the heating chamber, so that the hottest portion of the pulsated gases does not come 1nto direct contact with the recuperators.

27. 'The combination with a heating chamber, of storage chambers on two opposite 'sides thereof, means for supplying hot burned gases at points between the heating chamber and the storage chambers, a reciprocating device for gases whereby hot burned waste gases are pushed from one storage chamber to the other through the heating chamber and past the supply points for hot gases, discharge openings for surplus gases adjacent to the reciprocating device, and means for effecting recuperation of heat from the surplus waste gases located between the storage chambers and the discharge openings.

28. A method of heating which consists in quickly pulsating a body of hot gases back and forth between storage chambers A through the space to be heated and through flues connecting said space with said chambers, and maintaining the temperature of the body of hot gases by adding new gases of higher temperature to it when it passes through the connecting flues.

- 29. The combination with a heating chamber, of a storage chamber, a connecting flue between the two, means for pulsating hot gases back and forth from the heatin chamber through the connecting flue into t e storage chamber and back through the same connecting flue into the heating chamber,

and means for adding hot ases to the pulsated gases while passing t rough the con necting flue.

FRANZ PUENING. 

